Angiotensin converting enzyme in cerebrospinal fluid: a new assay.

Serum and CSF angiotensin converting enzyme (ACE) were measured by a new inhibitor binding assay in 32 patients with sarcoidosis, 49 with neurologic diseases, and 38 controls. In neurosarcoidosis, 11 of 20 patients had high levels of CSF ACE. In systemic sarcoidosis without neurologic abnormality, only 1 of 12 patients had elevated CSF ACE. The highest value was observed in a patient with widespread meningeal sarcoidosis. High values were also observed in patients with bacterial meningitis or malignant tumors of the CNS. Fluctuation in successive analyses correlated to clinical course of neurosarcoidosis. CSF ACE analysis seems useful in diagnosis and follow-up of neurosarcoidosis.